U.S. patent application number 15/124293 was filed with the patent office on 2017-01-19 for 2-cyanoacrylate adhesive composition.
The applicant listed for this patent is TOAGOSEI CO., LTD.. Invention is credited to Yushi ANDO, Kenichi ISHIZAKI.
Application Number | 20170015814 15/124293 |
Document ID | / |
Family ID | 54071604 |
Filed Date | 2017-01-19 |
United States Patent
Application |
20170015814 |
Kind Code |
A1 |
ISHIZAKI; Kenichi ; et
al. |
January 19, 2017 |
2-CYANOACRYLATE ADHESIVE COMPOSITION
Abstract
An adhesive composition is provided which exhibits an excellent
adhesion rate on metals and low-polarity thermoplastic elastomers,
and is excellent in appearance with no clouding of hardened bodies
and is good in storage stability. It is a 2-cyanoacrylate-based
adhesive composition which includes (a) a 2-cyanoacrylic acid ester
and (b) an onium salt represented by the general formula:
C.sup.+A.sup.-(1) where, in formula (1), C.sup.+ represents an
onium cation, and A.sup.- represents a bis(fluorosulfonyl)imide
anion.
Inventors: |
ISHIZAKI; Kenichi;
(Nagoya-shi, JP) ; ANDO; Yushi; (Nagoya-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOAGOSEI CO., LTD. |
Tokyo |
|
JP |
|
|
Family ID: |
54071604 |
Appl. No.: |
15/124293 |
Filed: |
February 27, 2015 |
PCT Filed: |
February 27, 2015 |
PCT NO: |
PCT/JP2015/055827 |
371 Date: |
September 7, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08K 5/43 20130101; C08F
222/32 20130101; C08K 5/3445 20130101; C08K 5/42 20130101; C08K
5/19 20130101; C09J 4/00 20130101; C08K 5/3462 20130101; C09J
2301/408 20200801; C09J 135/04 20130101; C09J 2425/006 20130101;
C08K 5/3432 20130101; C09J 4/00 20130101; C08F 222/32 20130101 |
International
Class: |
C08K 5/43 20060101
C08K005/43; C08K 5/19 20060101 C08K005/19; C08K 5/3445 20060101
C08K005/3445; C08K 5/3462 20060101 C08K005/3462; C09J 135/04
20060101 C09J135/04; C09J 7/02 20060101 C09J007/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 12, 2014 |
JP |
2014-048607 |
Claims
1. A 2-cyanoacrylate-based adhesive composition which comprises (a)
a 2-cyanoacrylic acid ester and (b) an onium salt represented by
the following formula (1): C.sup.+A.sup.- (1) wherein, C.sup.+
represents an onium cation, and A.sup.- represents a
bis(fluorosulfonyl)imide anion.
2. The 2-cyanoacrylate-based adhesive composition according to
claim 1, wherein the cation of the onium salt (b) is at least one
onium cation selected from a group consisting of a quaternary
ammonium cation, an imidazolium cation, a pyridinium cation, and a
tertiary sulfonium cation.
3. The 2-cyanoacrylate-based adhesive composition according to
claim 1, wherein the content of the onium salt (b) is 10 to 20,000
ppm relative to 100 parts by mass of the 2-cyanoacrylic acid ester
(a).
4. The 2-cyanoacrylate-based adhesive composition according to
claim 2, wherein the content of the onium salt (b) is 10 to 20,000
ppm relative to 100 parts by mass of the 2-cyanoacrylic acid ester
(a).
Description
TECHNICAL FIELD
[0001] The present invention relates to a 2-cyanoacrylate-based
adhesive composition containing a 2-cyanoacrylic acid ester as the
principal component.
BACKGROUND ART
[0002] A 2-cyanoacrylate-based adhesive composition quickly
establishes a strong bonding among various types of materials based
on the unique anion polymerization characteristics exhibited by its
principal component, 2-cyanoacrylic acid ester, which initiates
polymerization under the presence of weak anion provided by slight
moisture or the like attached to a surface of an adherend.
Accordingly, it is used as the so-called instantaneous adhesive in
a wide range of fields including industrial, medical, and household
applications. However, since the setting of the
2-cyanoacrylate-based adhesive composition proceeds by anion
polymerization, problems of lowered adhesion rate and insufficient
adhesion strength resulting from inhibition of anion polymerization
have been found when adherends are made of wood which is acidic or
a metal which easily forms an oxide skin. Furthermore, problems of
anion polymerization suppression and lowered adhesion rate have
been found when adherends are made of a thermoplastic elastomer or
the like that is low in polarity. To overcome such problems,
various types of additives have been proposed heretofore. For
instance, Patent Document 1 discloses an adhesive composition
containing crown ethers, and Patent Document 2 discloses an
adhesive composition containing polyalkylene oxides. Further,
Patent Documents 3 and 4 disclose adhesive compositions containing
calixarenes. Furthermore, Patent Document 5 describes using a phase
transfer catalyst as a hardening accelerator for the
2-cyanoacrylate-based composition.
CONVENTIONAL TECHNICAL DOCUMENTS
Patent Documents
[0003] Patent Document 1: Japanese Patent Publication (Laid-open)
No. Sho. 53-129231
[0004] Patent Document 2: Japanese Patent Publication (Laid-open)
No. Sho. 63-128088
[0005] Patent Document 3: Japanese Patent Publication (Laid-open)
No. Sho. 60-179482
[0006] Patent Document 4: Japanese Patent Publication (Laid-open)
No. 2000-44891
[0007] Patent Document 5: British Patent Publication GB2228943
specification
SUMMARY OF INVENTION
Problems to be Solved by the Invention
[0008] The adhesive compositions disclosed in Patent Documents 1 to
4 have accelerated adhesion rate for various adherends, however,
with increasing demand on productivity, the adhesion rate is still
unsatisfactory when adherends are of metals or low-polarity
thermoplastic elastomers. Further, even in the case of using the
phase transfer catalyst specifically described in Patent Document 5
as hardening accelerator, the adhesion rate is still insufficient
when adherends are metals or low-polarity thermoplastic
elastomers.
[0009] In addition, the adhesive compositions containing crown
ethers or polyalkylene oxides as disclosed in Patent Documents 1
and 2 have a problem of clouding of hardened bodies when adherends
are of EPDM, a methacrylic resin or the like. The adhesive
compositions containing calixarene derivatives as disclosed in
Patent Documents 3 and 4 also have the problem of clouding of
hardened materials when adherends are of soft PVC.
[0010] The present invention is made in light of the aforementioned
circumstances, and aims at providing an adhesive composition having
good storage stability and exhibiting an excellent adhesion rate
for metals and low-polarity thermoplastic elastomers. Also, it aims
at providing an adhesive composition that gives a hardened body
free from clouding and thus excellent in appearance for a wide
range of adherends.
Means for Solving the Problems
[0011] The present inventors have found that an adhesive
composition which is excellent in appearance of hardened bodies and
storage stability and exhibits an excellent adhesion rate for
metals and low-polarity thermoplastic elastomers can be obtained by
blending an onium salt having a specific structure with a
2-cyanoacrylic acid ester, and have accomplished the present
invention.
[0012] The present invention is as follows:
[0013] 1. A 2-cyanoacrylate-based adhesive composition which
comprises (a) a 2-cyanoacrylic acid ester and (b) an onium salt
represented by the following general formula (1):
C.sup.+A.sup.- (1)
wherein, in formula (1), C.sup.+ represents an onium cation, and
A.sup.- represents a bis(fluorosulfonyl)imide anion.
[0014] 2. The 2-cyanoacrylate-based adhesive composition according
to the above item 1, wherein the cation of the onium salt (b) is at
least one onium cation selected from a group consisting of a
quaternary ammonium cation, an imidazolium cation, a pyridinium
cation, and a tertiary sulfonium cation.
[0015] 3. The 2-cyanoacrylate-based adhesive composition according
to the above items 1 or 2, wherein the content of the onium salt
(b) is 10 to 20,000 ppm relative to 100 parts by mass of the
2-cyanoacrylic acid ester (a).
Effect of the Invention
[0016] Since the 2-cyanoacrylate-based adhesive composition
according to the present invention contains a 2-cyanoacrylic acid
ester and an onium salt having a specific structure, it not only
exhibits an excellent adhesion rate for metals and low-polarity
thermoplastic elastomers, but also has good storage stability. In
addition, the above adhesive composition gives hardened bodies
excellent in appearance since it does not cause clouding in
hardened bodies when used for bonding, filling or potting of a wide
range of adherends.
DESCRIPTION OF EMBODIMENTS
[0017] Details of the 2-cyanoacrylate-based adhesive composition
(which is hereinafter often simply referred to as "adhesive
composition") according to the present invention are described
below.
[0018] The adhesive composition of the present invention contains
(a) a 2-cyanoacrylic acid ester and (b) an onium salt having a
specific structure.
[0019] As the "(a) 2-cyanoacrylic acid ester", 2-cyanoacrylic acid
esters generally employed in this type of adhesive compositions can
be used without any particular restriction. The 2-cyanoacrylic acid
ester includes methyl, ethyl, chloroethyl, n-propyl, i-propyl,
allyl, propargyl, n-butyl, i-butyl, n-pentyl, n-hexyl, cyclohexyl,
phenyl, tetrahydrofurfuryl, heptyl, 2-ethylhexyl, n-octyl, 2-octyl,
n-nonyl, oxononyl, n-decyl, n-dodecyl, methoxyethyl, methoxypropyl,
methoxyisopropyl, methoxybutyl, ethoxyethyl, ethoxypropyl,
ethoxyisopropyl, propoxymethyl, propoxyethyl, isopropoxyethyl,
propoxypropyl, butoxymethyl, butoxyethyl, butoxypropyl,
butoxyisopropyl, butoxybutyl, 2,2,2-trifluoroethyl, and
hexafluoroisopropyl esters of 2-cyanoacrylic acid. These
2-cyanoacrylic acid esters can be used alone or in combination of
two or more. Furthermore, among these 2-cyanoacrylic acid esters,
2-cyanoacrylic acid esters having an alkyl group with 3 or less
carbon atoms are preferred since they are excellent in curability,
and ethyl 2-cyanoacrylate is more preferred.
[0020] The adhesive composition according to the present invention
contains "(b) an onium salt represented by the following general
formula (1)". The onium salt functions as a hardening accelerator
of the adhesive composition, and particularly is a compound which
improves the adhesion rate for metals and thermoplastic
elastomers.
C.sup.+A.sup.- (1)
wherein, in formula (1), C.sup.+ represents an onium cation, and
A.sup.- represents a bis(fluorosulfonyl)imide anion.
[0021] The cations of the onium salt are not particularly limited
as long as they can impart solubility in 2-cyanoacryalte to the
onium salt, and include, for example, an onium cation represented
by the following general formula (2), an imidazolium cation, a
pyridinium cation, and an onium cation represented by the following
general formula (3).
##STR00001##
wherein, in formula (2), R.sup.3 to R.sup.6 each independently
represents a non-substituted or substituted alkyl group, cycloalkyl
group, aryl group, aralkyl group, alkenyl group or alkynyl group;
otherwise, part or all of R.sup.3 to R.sup.6 may form a
non-substituted or substituted 3 to 10 membered ring together with
the atom represented by A wherein the ring may contain a hetero
atom such as O and S, provided that R.sup.3 to R.sup.6 which do not
involve the formation of the ring are the same as defined
hereinbefore; and A represents a nitrogen atom or phosphorus atom.
Specific examples of the above substituted alkyl group include, for
example, an alkoxy group and an alkanoyl group. The above
non-substituted or substituted alkyl group preferably has 1 to 20
carbon atoms, and more preferably 1 to 16 carbon atoms. When part
of R.sup.3 to R.sup.6 form a ring, the ring is, in general,
constituted by 2 to 3 of R.sup.3 to R.sup.6. Specific examples of
the compound represented by the formula (2) in which two of R.sup.3
to R.sup.6 form a ring include piperidinium cation, morpholinium
cation, and pyrrolidinium cation.
##STR00002##
wherein, in formula (3), R.sup.7 to R.sup.9 each independently
represents a non-substituted or substituted alkyl group, cycloalkyl
group, aryl group, aralkyl group, alkenyl group or alkynyl group;
otherwise, part or all of R.sup.7 to R.sup.9 may form a
non-substituted or substituted 3 to 10 membered ring together with
the sulfur atom wherein the ring may contain a hetero atom such as
O and S, provided that R.sup.7 to R.sup.9 which do not involve the
formation of the ring are the same as defined hereinbefore.
Specific examples of the above substituted alkyl group include, for
example, an alkoxy group and an alkanoyl group. The above
non-substituted or substituted alkyl group preferably has 1 to 20
carbon atoms, and more preferably 1 to 16 carbon atoms.
[0022] Representative examples of the onium cations represented by
the formula (2) include quaternary ammonium cations, quaternary
phosphonium cations, and the like.
[0023] Specific examples of the quaternary ammonium cations include
tetraalkylammonium cations such as [0024] tetramethylammonium,
ethyltrimethylammonium, [0025] diethyldimethylammonium,
triethylmethylammonium, [0026] tetraethylammonium,
tetra-n-butylammonium, [0027] trimethyl-n-propylammonium,
trimethyl-isopropylammonium, [0028] n-butyltrimethylammonium,
isobutyltrimethylammonium, [0029] t-butyltrimethylammonium,
n-hexyltrimethylammonium, [0030] dimethyldi-n-propylammonium,
dimethyldiisopropylammonium, [0031]
dimethyl-n-propylisopropylammonium, [0032]
methyltri-n-propylammonium, methyltri-isopropylammonium, [0033]
methyldi-n-propylisopropylammonium, [0034]
methyl-n-propyldiisopropylammonium, [0035]
triethyl-n-propylammonium, triethylisopropylammonium, [0036]
n-butyltriethylammonium, triethylisobutylammonium, [0037]
t-butyltriethylammonium, di-n-butyldimethylammonium, [0038]
diisobutyldimethylammonium, di-t-butyldimethylammonium, [0039]
n-butylethyldimethylammonium, [0040] isobutylethyldimethylammonium,
[0041] t-butylethyldimethylammonium, [0042]
n-butylisobutyldimethylammonium, [0043]
n-butyl-t-butyldimethylammonium, [0044]
t-butylisobutyldimethylammonium, [0045] diethyldi-n-propylammonium,
diethyldiisopropylammonium, [0046]
diethyl-n-propylisopropylammonium, [0047]
ethyltri-n-propylammonium, ethyltriisopropylammonium, [0048]
ethylisopropyldi-n-propylammonium, [0049]
ethyldiisopropyl-n-propylammonium, [0050]
diethylmethyl-n-propylammonium, [0051]
ethyldimethyl-n-propylammonium, [0052]
ethylmethyldi-n-propylammonium, [0053]
diethylisopropylmethylammonium, [0054]
ethylisopropyldimethylammonium, [0055]
ethyldiisopropylmethylammonium, [0056]
ethylmethyl-n-propylisopropylammonium, [0057]
tetra-n-propylammonium, tetra-isopropylammonium, [0058]
tri-isopropyl-n-propylammonium, [0059]
diisopropyldi-n-propylammonium, [0060]
isopropyl-tri-n-propylammonium, butyltrimethylammonium, [0061]
trimethylpentylammonium, hexyltrimethylammonium, [0062]
heptyltrimethylammonium, trimethyloctylammonium, [0063]
trimethylnonylammonium, decyltrimethylammonium, [0064]
trimethylundecylammonium, dodecyltrimethylammonium, [0065]
didecyldimethylammonium, dilauryldimethylammonium, [0066]
dimethyldistyrylammonium, dimethyldioctadecylammonium, [0067]
dimethyldioctylammonium, dimethyldipalmitylammonium, [0068]
ethylhexadecyldimethylammonium, [0069] hexyldimethyloctylammonium,
[0070] dodecyl(ferrocenylmethyl)dimethylammonium, N-methyl
homatropinium and the like; aromatic alkyl-group substituted
ammonium cations such as [0071] benzyltrimethylammonium,
benzyltributylammonium, [0072] benzyldodecyldimethylammonium, and
the like; aromatic substituted ammonium cations such as [0073]
trimethylphenylammonium, tetraphenylammonium, and the like; and
aliphatic cyclic ammonium cations such as [0074] pyrrolydinium
(such as 1,1-dimethylpyrrolydinium, [0075]
1-ethyl-1-methylpyrrolydinium, 1,1-diethylpyrrolydinium, [0076]
1,1-tetramethylenepyrrolydinium, and [0077]
1-butyl-1-methylpyrrolydinium), piperidinium (such as
1,1-dimethylpiperidinium, 1-ethyl-1-methyl piperidinium, [0078]
1,1-diethylpiperidinium, and [0079] 1-butyl-1-methylpiperidinium),
and morpholinium (such as 1,1-dimethylmorpholinium,
1-ethyl-1-methylmorpholinium, and 1,1-diethylmorpholinium).
[0080] Specific examples of the quaternary phosphonium cations
include cations such as tetramethylphosphonium,
triethylmethylphosphonium, and tetraethylphosphonium.
[0081] Specific examples of the imidazolium cations include cations
such as 1,3-dimethylimidazolium, [0082] 1,2,3-trimethylimidazolium,
1-ethyl-3-methylimidazolium, [0083]
1-ethyl-2,3-dimethylimidazolium, [0084]
1-methyl-3-n-octylimidazolium, [0085] 1-hexyl-3-methylimidazolium,
1,3-diethylimidazolium, [0086] 1,2-diethyl-3-methylimidazolium,
[0087] 1,3-diethyl-2-methylimidazolium, [0088]
1,2-dimethyl-3-n-propylimidazolium, [0089]
1-n-butyl-3-methylimidazolium, [0090]
1-n-butyl-2,3-dimethylimidazolium, [0091]
1,2,4-trimethyl-3-n-propylimidazolium, [0092]
1,2,3,4-tetramethylimidazolium, [0093]
1,2,3,4,5-pentamethylimidazolium, [0094]
2-ethyl-1,3-dimethylimidazolium, [0095]
1,3-dimethyl-2-n-propylimidazolium, [0096]
1,3-dimethyl-2-n-pentylimidazolium, [0097]
2-n-heptyl-1,3-dimethylimidazolium, [0098]
1,3,4-trimethylimidazolium, [0099]
2-ethyl-1,3,4-trimethylimidazolium, [0100]
1,3-dimethylbenzimidazolium, 3-methyl-1-phenylimidazolium, [0101]
1-benzyl-3-methylimidazolium, [0102]
2,3-dimethyl-1-phenylimidazolium, [0103]
1-benzyl-2,3-dimethylimidazolium, [0104]
1,3-dimethyl-2-phenylimidazolium, [0105]
2-benzyl-1,3-dimethylimidazolium, [0106]
1,3-dimethyl-2-n-undecylimidazolium, and [0107]
1,3-dimethyl-2-n-heptadecylimidazolium.
[0108] The pyridinium cations include cations such as [0109]
1-methylpyridinium, 1-ethylpyridinium, [0110] 1-n-propylpyridinium,
1-isopropylpyridinium, [0111] 1-n-butylpyridinium, and
1-n-butyl-3-methylpyridinium.
[0112] Specific examples of the tertiary sulfonium cations
represented by the general formula (3) above include cations such
as trimethylsulfonium, triethylsulfonium, tripropylsulfonium, and
triphenylsulfonium.
[0113] Among the aforementioned onium cations, preferred are
quaternary ammonium cations, imidazolium cations, pyridinium
cations, or tertiary sulfonium cations from the viewpoint of
exhibiting excellent solubility to 2-cyanoacrylic acid ester and
good balance between high curing acceleration property and storage
stability of the adhesive composition; and further preferred are
quaternary ammonium cations, imidazolium cations or pyridinium
cations.
[0114] Next, the anion of the onium salt is a
bis(fluorosulfonyl)imide anion. Since the bis(fluorosulfonyl)imide
anion has little nucleophilicity, it has no adverse effect on
storage stability of the adhesive composition even when it is
present as an onium salt in the adhesive composition. On the other
hand, since the conjugate acid for the above anion is strongly
acidic, it reacts with a very small amount of salts or the like
present on the surface of an adherend to liberate an anion that has
nucleophilicity and thus can become a polymerization initiator for
2-cyanoacryltes. As a result, excellent adhesion rate can be
exhibited even when an adherend is of a metal or a low-polarity
thermoplastic elastomer.
[0115] The onium salt used in the present invention is not
particularly limited so long as it is a combination of the cations
and the anions described hereinbefore. Examples of the onium salt
include tetraethylammonium [0116] bis(fluorosulfonyl)imide, [0117]
tetra-n-butylammonium bis(fluorosulfonyl)imide, [0118]
methyltri-n-octylammonium bis(fluorosulfonyl)imide, [0119] dodecyl
trimethylammonium bis(fluorosulfonyl) imide, [0120]
1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide, [0121]
1-ethyl-2,3-dimethylimidazolium bis(fluorosulfonyl)imide, [0122]
1-butyl-3-methylimidazolium bis(fluorosulfonyl)imide, [0123]
1-butyl-2,3-dimethylimidazolium bis(fluorosulfonyl)imide, [0124]
1-ethyl-1-methylpiperidinium bis(fluorosulfonyl)imide, [0125]
1-butyl-1-methylpiperidinium bis(fluorosulfonyl)imide, [0126]
1-ethyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide, [0127]
1-butyl-1-methylpyrrolidinium bis(fluorosulfonyl)imide, [0128]
1-methyl-1-propylpyrrolidinium bis(fluorosulfonyl)imide, [0129]
4-methyl-1-octylpyridinium bis(fluorosulfonyl)imide, [0130] 1-ethyl
pyridinium bis(fluorosulfonyl)imide, [0131]
1-ethyl-3-methylpyridinium bis(fluorosulfonyl)imide, [0132]
1-butyl-3-methylpyridinium bis(fluorosulfonyl)imide, [0133]
triethylsulfonium bis(fluorosulfonyl)imide, and [0134]
triethylmethylphosphonium bis(fluorosulfonyl) imide. [0135] These
onium salts may be used alone or in combination of two or more.
[0136] The onium salt according to the present invention can be
prepared by methods known in the art. For example, they can be
prepared by obtaining a bis(fluorosulfonyl)imide anion from urea
and fluorosulfonic acid as described in Martin Beran et al., Z.
Anorg. Allg. Chem., 2005, 631, 55-59, followed by reaction with a
corresponding onium halide as described in Hiroyuki Ohno et al., J.
Am. Chem. Soc., 2005, 27, 2398-2399 or Peter Wasserscheid et al.,
Green Chemistry, 2002, 4, 134-138.
[0137] The content of the aforementioned onium salt (b) in the
adhesive composition is, preferably from 10 to 20000 ppm, more
preferably from 25 to 15000 ppm, and further preferably from 50 to
10000 ppm, per 100 parts by mass of 2-cyanoacrylic acid ester (a).
When the content is within the above range, the effect of hardening
acceleration is sufficiently exhibited, and the storage stability
of the adhesive composition is kept good.
[0138] The reason why the aforementioned onium salt improves the
adhesion rate on metals and thermoplastic elastomers without
impairing the storage stability of the adhesive composition is not
yet clear, however, can be presumed as follows. Since the conjugate
acid of the weakly nucleophilic anion that constitutes the onium
salt is a strong acid, it releases an anion which is nucleophilic
and thus serves as a polymerization initiator of the 2-cyanoacrylic
acid ester when it reacts with a salt that is present on a surface
of an adherend. On the other hand, since such a salt is not present
during storage, the aforementioned anion exchange reaction does not
take place to initiate the release of the highly reactive anion, so
that excellent storage stability is maintained.
[0139] The adhesive composition of the present invention may
contain, in addition to the aforementioned onium salts, another
hardening accelerator conventionally blended in these types of
adhesive compositions. Examples of such hardening accelerators
include polyalkylene oxides, crown ethers, silacrown ethers,
calixarenes, cyclodextrins, and pyrogallol-based cyclic
compounds.
[0140] The polyalkylene oxides refer to polyalkylene oxides and the
derivatives thereof, and examples thereof include those disclosed
in Japanese Patent Publication (Kokoku) No. Sho. 60-37836, Japanese
Patent Publication (Kokoku) No. Hei. 1-43790, Japanese Patent
Publication (Laid-open) No. Sho.
[0141] 63-128088, Japanese Patent Publication (Laid-open) No. Hei.
3-167279, U.S. Pat. No. 4,386,193, and U.S. Pat. No. 4,424,327.
Concrete examples thereof include (1) polyalkylene oxides such as
diethylene glycol, triethylene glycol, polyethylene glycol, and
polypropylene glycol; and (2) derivatives of polyalkylene oxides
such as polyethylene glycol monoalkyl esters, polyethylene glycol
dialkyl esters, polypropylene glycol dialkyl esters, diethylene
glycol monoalkyl ethers, diethylene glycol dialkyl ethers,
dipropylene glycol monoalkyl ethers, and dipropylene glycol dialkyl
ethers.
[0142] Examples of the crown ethers include those disclosed in, for
instance, Japanese Patent Publication (Kokoku) No. Sho. 55-2238 and
Japanese Patent Publication (Laid-Open) No. Hei. 3-167279. Concrete
examples thereof include [0143] 12-crown-4, 15-crown-5, 18-crown-6,
benzo-12-crown-4, [0144] benzo-15-crown-5, benzo-18-crown-6,
dibenzo-18-crown-6, [0145] dibenzo-24-crown-8, dibenzo-30-crown-10,
[0146] tribenzo-18-crown-6, asym-dibenzo-22-crown-6, [0147]
dibenzo-14-crown-4, dicyclohexyl-24-crown-8, [0148]
cyclohexyl-12-crown-4, 1,2-decalyl-15-crown-5, [0149]
1,2-naphtho-15-crown-5, 3,4,5-naphthyl-16-crown-5, [0150]
1,2-methylbenzo-18-crown-6, 1,2-tert-butyl-18-crown-6, and
1,2-vinylbenzo-15-crown-5. Examples of the silacrown ethers
include, for example, those disclosed in Japanese Patent
Publication (Laid-Open) No. Sho. 60-168775. Concrete examples
thereof include dimethylsila-11-crown-4, dimethylsila-14-crown-5,
and dimethylsila-17-crown-6.
[0151] Examples of the calixarenes include those disclosed in
Japanese Patent Publication (Laid-Open) No. Sho. 60-179482,
Japanese Patent Publication (Laid-Open) No. Sho. 62-235379, and
Japanese Patent Publication (Laid-Open) No. Sho. 63-88152. Concrete
examples thereof include [0152] 5, 11, 17, 23, 29,
35-hexa-tert-butyl-37, 38, 39, 40, 41, 42-hexahydroxycalix[6]arene,
[0153] 37, 38, 39, 40, 41, 42-hexahydroxycalix [6] arene, [0154]
37, 38, 39, 40, 41, 42-hexa-(2-oxo-2-ethoxy)-ethoxycalix [6] arene,
25, 26, 27, 28-tetra-(2-oxo-2-ethoxy)-ethoxycalix [4]arene, and
tetraethyl [0155] 4-tert-butylcalix[4] arene-O, O', O'',
O'''-tetraacetate. [0156] Examples of the cyclodextrins include
those disclosed in Japanese Patent Publication (Kohyo) No. Hei.
5-505835. Concrete examples thereof include .alpha.-, .beta.-, or
.gamma.-cyclodextrins. Examples of the pyrogallol-based cyclic
compounds include compounds disclosed in Japanese Patent
Publication (Laid-Open) No. 2000-191600. Concrete examples thereof
include 3, 4, 5, 10, 11, 12, 17, 18, 19, 24, 25,
26-dodecaethoxycarbomethoxy-C-1, C-8, C-15,
C-22-tetramethyl[14]-metacyclophane. These hardening accelerators
may be used either alone or in combination of two or more
thereof.
[0157] In the adhesive composition, the content of the hardening
accelerators other than the onium salt is preferably from 10 to
30000 ppm, more preferably from 50 to 20000 ppm, and most
preferably from 100 to 10000 ppm relative to 100 parts by mass of
2-cyanoacrylic acid ester. The adhesive composition can be improved
in the adhesion rate on various adherends without impairing the
storage stability so long as the content falls within the range of
from 10 to 30000 ppm.
[0158] In addition to the above hardening accelerator, the adhesive
composition of the present invention may contain stabilizers,
plasticizers, thickeners, particles, colorants, fragrances,
solvents, strength improvers or others that have conventionally
been employed in adhesive compositions containing 2-cyanoacrylic
acid ester, depending on the objectives, in proper amounts that do
not impair curability, adhesion strength or the like of the
adhesive composition.
[0159] The stabilizers include (1) anion polymerization inhibitors,
such as sulfur dioxide, aliphatic sulfonates such as
methanesulfonate, aromatic sulfonates such as p-toluenesulfonate,
boron trifluoride complexes such as boron trifluoride methanol and
boron trifluoride diethyl ether, HBF.sub.4, and trialkyl borate;
and (2) radical polymerization inhibitors such as hydroquinone,
hydroquinone monomethyl ether, t-butylcatechol, catechol, and
pyrogallol. These stabilizers may be used alone, or in a
combination of two or more thereof.
[0160] The plasticizers include triethyl acetyl citrate, tributyl
acetyl citrate, dimethyl adipate, diethyl adipate, dimethyl
sebacate, dimethyl phthalate, diethyl phthalate, dibutyl phthalate,
diisodecyl phthalate, dihexyl phthalate, diheptyl phthalate,
dioctyl phthalate, bis(2-ethylhexyl) phthalate, diisononyl
phthalate, diisotridecyl phthalate, dipentadecyl phthalate, dioctyl
terephthalate, diisononyl isophthalate, decyl toluate,
bis(2-ethylhexyl) camphorate, 2-ethylhexylcyclohexyl carboxylate,
diisobutyl fumarate, diisobutyl maleate, caproic triglyceride,
2-ethylhexyl benzoate, and dipropylene glycol dibenzoate. Among
them, preferred from the viewpoint of good miscibility with
2-cyanoacrylic acid ester and of high plasticizing efficiency are
tributyl acetyl citrate, dimethyl adipate, dimethyl phthalate,
2-ethylhexyl benzoate, and dipropylene glycol dibenzoate. These
plasticizers may be used alone or in combination of two or more
thereof.
[0161] The thickeners include polymethylmethacrylates, copolymers
of methylmethacrylate and an acrylate, copolymers of
methylmethacrylate and another methacrylate, acrylic rubbers,
polyvinylchloride, polystyrene, cellulose esters,
polyalkyl-2-cyanoacrylate, and ethylene-vinyl acetate copolymers.
These thickeners may be used either alone or in combination of two
or more thereof.
EXAMPLES
[0162] The present invention is explained in further detail byway
of Examples below. However, the present invention is not limited to
these Examples, but various modifications and changes can be made
to the present invention without departing from the gist of the
present invention. In the description below, parts and percentages
are based on mass unless otherwise mentioned.
1. Evaluation Method
[0163] (1) Adhesion Rate
[0164] The adhesion rate was measured at 23.degree. C. under 60%
RH, in accordance with JIS K 6861 "Testing methods for
.alpha.-cyanoacrylate adhesives". The test pieces used in the
measurement were as follows.
[0165] Aluminum: Aluminum test piece (material: A1050P),
manufactured by Nippon Testpanel Co., Ltd.
[0166] Iron: Iron test piece (material: S10C), manufactured by
Nippon Testpanel Co., Ltd.
[0167] Styrene thermoplastic elastomer: "ACTYMER AE-2060S" (trade
name), manufactured by RIKEN TECHNOS CORP. [0168] (2) Viscosity
[0169] Viscosity was measured using E-type viscometer at 25.degree.
C. and 100 rpm. [0170] (3) Storage Stability
[0171] Evaluation was made by comparing the adhesion rate and
viscosity measured at the initial stage with the adhesion rate and
viscosity measured after storage for two weeks under the
environment of 50.degree. C. and 95% RH. For the storage, 1.5 g of
the adhesive composition was sealed in a 2 g polyethylene
container. [0172] (4) Appearance After Cured
[0173] Several drops of the adhesive composition were placed on
EPDM (ethylene propylene rubber) and soft PVC (polyvinyl chloride)
plates of 25 mm(length).times.50 mm(width).times.3 mm(thickness),
and were allowed to set under the environment of 23.degree. C. and
60% RH for 3 days. The appearance of the hardened body was observed
and indicated by "o" or "X". "o" indicates that no clouding or
wrinkle was observed on the hardened body, whereas "X" indicates
that clouding or wrinkle was observed on the hardened body. The
test pieces used were as follows. [0174] EPDM: EPDM-5065/3t,
manufactured by CHUKYOGOMU CORPORATION, [0175] Soft PVC: TOUGHNYL
D-Blue (trade name), manufactured by Japan Wavelock Co., Ltd.
2. Preparation of 2-Cyanoacrylate-Based Adhesive Composition
Example 1
[0176] To ethyl 2-cyanocrylate were added 40 ppm of sulfur dioxide
and 1000 ppm of hydroquinone (with respect to 100 parts by mass of
ethyl 2-cyanocrylate), and 100 ppm (refer to Table 1) of
1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide ("ELEXCEL
AS-110" (trade name) manufactured by DKS Co. Ltd.) was blended
therewith. The resulting blend was stirred to mix for 30 minutes
under room temperature (15 to 30.degree. C.) to produce an adhesive
composition. The thus-obtained adhesive composition was subjected
to evaluation of adhesion rates on aluminum, iron and thermoplastic
elastomer, viscosity, storage stability, and appearance of hardened
body. The results are given in Table 2.
Examples 2 to 10 and Comparative Examples 1 to 4
[0177] Adhesive compositions were produced and evaluated in the
same manner as in Example 1, except that the onium salt or
hardening accelerator to be blended with the adhesive compositions
was changed as shown in Tables 1 and 3. The results are given in
Tables 2 and 4.
TABLE-US-00001 TABLE 1 Onium salt Content Type (ppm) Example 1
1-ethyl-3-methylimidazolium ELEXCEL AS-110, manufactured by DKS Co.
Ltd. 100 bis(fluorosulfonyl)imide 2 1-ethyl-3-methylimidazolium
ELEXCEL AS-110, manufactured by DKS Co. Ltd. 250
bis(fluorosulfonyl)imide 3 1-ethyl-3-methylimidazolium ELEXCEL
AS-110, manufactured by DKS Co. Ltd. 500 bis(fluorosulfonyl)imide 4
1-ethyl-3-methylimidazolium ELEXCEL AS-110, manufactured by DKS Co.
Ltd. 2000 bis(fluorosulfonyl)imide 5 4-methyl-1-octylpyridinium
ELEXCEL AS-804, manufactured by DKS Co. Ltd. 500
bis(fluorosulfonyl)imide 6 4-methyl-1-octylpyridinium ELEXCEL
AS-804, manufactured by DKS Co. Ltd. 1000 bis(fluorosulfonyl)imide
7 4-methyl-1-octylpyridinium ELEXCEL AS-804, manufactured by DKS
Co. Ltd. 10000 bis(fluorosulfonyl)imide 8 dodecyltrimethylammonium
MP-402, manufactured by DKS Co. Ltd. 100 bis(fluorosulfonyl)imide 9
dodecyltrimethylammonium MP-402, manufactured by DKS Co. Ltd. 250
bis(fluorosulfonyl)imide 10 dodecyltrimethylammonium MP-402,
manufactured by DKS Co. Ltd. 500 bis(fluorosulfonyl)imide
TABLE-US-00002 TABLE 2 Initial After 2 weeks (50.degree. C., 95%
RH) Adhesion rate Adhesion rate Appearance (seconds) (seconds)
after cured Thermo- Thermo- On Alumi- plastic Viscosity Alumi-
plastic Viscosity On Soft num Iron Elastomer (mPa s) num Iron
Elastomer (mPa s) EPDM PVC Examples 1 30 30 60 2.2 30 30 60 2.4
.largecircle. .largecircle. 2 30 20 30 2.2 30 20 45 2.4
.largecircle. .largecircle. 3 20 15 30 2.2 20 20 30 2.5
.largecircle. .largecircle. 4 10 10 20 2.6 20 20 30 3.1
.largecircle. .largecircle. 5 30 30 45 2.4 30 30 45 2.7
.largecircle. .largecircle. 6 20 20 30 2.7 30 20 45 3.0
.largecircle. .largecircle. 7 10 10 20 3.0 30 20 30 3.9
.largecircle. .largecircle. 8 30 30 60 2.3 30 30 60 2.5
.largecircle. .largecircle. 9 20 20 45 2.4 30 20 45 2.6
.largecircle. .largecircle. 10 15 15 30 2.5 20 15 30 2.7
.largecircle. .largecircle.
TABLE-US-00003 TABLE 3 Additive Content Type Trade name, etc. (ppm)
Comparative 1 15-Crown-5 Crown Ether 0-15, manufactured 2500
Examples by NIPPON SODA CO., LTD. 2 18-Crown-6 Reagent,
manufactured by Kishida 500 Chemical Co., Ltd. 3
Tetraethyl4-tert-butylcalix[4]arene- CALIX B4-EA, manufactured by
2000 O,O',O'',O'''-tetraacetate Sugai Chemical IND. CO., LTD. 4
Additive-free -- --
TABLE-US-00004 TABLE 4 Initial After 2 weeks (50.degree. C., 95%
RH) Adhesion rate Adhesion rate Appearance (seconds) (seconds)
after cured Thermo- Thermo- On Alumi- plastic Viscosity Alumi-
plastic Viscosity On Soft num Iron Elastomer (mPa s) num Iron
Elastomer (mPa s) EPDM PVC Comparative 1 45 45 180 2.1 45 45 180
2.5 X X Examples 2 60 60 120 2.1 90 60 180 3.7 X X 3 60 45 180 2.2
60 60 300 2.5 .largecircle. X 4 120 120 300 2.1 120 180 >300 2.1
X X
[0178] The results in Tables 2 and 4 show that the adhesive
compositions in Examples 1-10 exhibit excellent adhesion rates on
aluminum, iron and low-polarity thermoplastic elastomer, compared
with the conventional adhesive compositions (Comparative Examples
1-4). Also, it is found that the adhesive compositions according to
the present invention show a viscosity change of 1.5 or less even
after two weeks at 50.degree. C. and 95%RH, and thus are excellent
in storage stability, and are also excellent in appearance of
hardened bodies on both EPDM and soft PVC adherends.
INDUSTRIAL APPLICABILITY
[0179] The present invention which is based on 2-cyanoacrylic acid
ester can be utilized as a so-called instantaneous adhesive in a
wide range of products and technical fields in various types of
industrial fields including household and medical fields, and is
particularly useful for applications that require quick adhesion on
metallic or low-polarity adherends.
* * * * *